Electric switch



v J. H. HEWITT ELECTRIC SWITCH Nov. l5

Filed March 5, 1926 2 lbeets et l Nov. 15, 1927.

1,649,694 J. H. HEwlTT ELECTRI C SWITCH Filed March 5. 1926 2 Sheets-Sheet 2 Patented Nov. 15, 1927.

UNITED NSTATES PAKTENToFFiC'E. l

JOHN HERBERT `HEW'I'LT, 0F BIRMINGHAM, ENGLAND.

ELECTRIC SWITCH.

Applicationilcd March 5, 1926, Serial No. 92,585, and. in Great Britain February 2, 19.26.

lconducting parts shall be well separated to minimize capacity eitects.

One oi the objects of the present invention is to construct au improved switch of the kind in which the moving contacts are,

mounted on a rotary drum or hub and are preferably of skeleton form and adapted to engage with stationary contacts formed of strips of metal separately mounted in an insulator.

When used in wireless apparatus such switches commonly have to be mounted on a panel, and a further object oit' the present invention is to construct the switch so that its surface areawhen projected on to the panel is as small as possible, the construction being much more compact than the various arrangements described in my prior U. S. A. Patent No. 1,554,090.

A further important object of the invention is lto 'provide a switch operating on the jack principle by means of which an extraneous circuit is interposed in anyv desirable portion of a circuit; merely by inf p vbe made from a. single sheet metal blank serting a plug or jack which constitutes the two ends ot the extraneous circuit, said plug or jack consisting of two insulated members.

A further object of the present invention is to provide a switch wherein the terminals associated with the contacts kare easily accessible for wiring. u v

A further object ofthe present invention is to construct a switch of the kind referred to wherein thecost of manufacture is kept as low as possible and wherein the arrange-` ment is such that the switch can be. mounted on the panel by providinga single hole in the panel. i p A further object of the present invention .is to provide a switch of the kind referred to which can be operated by a member which is detachable from the switch, the switch being constructed so that a member of a particular shape must be used for its operation whereby the said operating member can be used as a key, preventing the unauthorized operation'of the switch. A v l.

Uriel` of the 'features `of the present inven tion is to provide a bracket er trame y tiret 1.

apportion or portions which rotatably support the drum or hub carrying the moving contact, the said bracket or frame having an attachment portion by which it is adaptedto `be secured to the panel, the said attachment portion'being parallel to the axis "of the drum or hub, and the attachment portion being provided with a hollow boss which engaged by an enlarged head upon the operating push rod so that the` push rod can beentirelydetached from the switch.

It the fork or recess associated with the hub is made of a particular shape, then a special shape of head and neck may be necessary on the operating push rod, in which case the operating push rod will serve as a key to prevent unauthorized operation of the switch.

The bracket or frame ofthe switch may having a portion 'for attachment to the underside ci the usual insulating panel and having integral ears which are bent at right angles to the attachment portion and which serve tocarry the drum or hub between them.

The said ears may be extended so that they `rnayfalso carry au `insulating plate which receives the stationary contacts, or a separate pair ot' ears may be provided integrally 'onthe said sheetmetal blank for carrying Figure 3 is a section on line l3--3 of Fig` ure 2.

Figure 4 is a section on line of Fig rig-are 5 is t View in enea-tica be arranged parallel with the operating member of the switch but at the opposite side of the hub; or it may be arranged at right angles to the operating member and be disposed between the hub and the insulating plate which carries the stationary contacts.

In the construction shown in Figures to it is necessary for the forked crank 34, on the hub 9 to be insulated from the other metal parts of the switch and accordingly it is mounted upon or associated with an insulating member 37 which forms a second crank and is connected by links 38 with the lever 39; one end 40 ot' which is hooked over a portion of the bracket and the other end 4l of which is connected by a coiled spring 42 to the bracket, the arrangement being such that the operation of the switch causes the crank to throw over a dead centre position so that the coiled spring 42 retains the switch in either terminal position. K

In all the arrangements described, the stationary cont-acts or the Shanks thereof are substantially parallel with the operating member although the effective ends of the stationary contacts are bent into suitable positions to co-operate with the moving contacts.

What- I claim then is l. An electric switch comprising a bracket having an attachment portion and having means for carrying a hub; an'insulating hub mounted in said hub carrying means for rockingy movement; movable ycontact members on said hub; stationary contact members; means for carrying said stationary contact members; a crank associated with said hub; a hollow boss in said bracket adapted to receive a sliding member for operating said crank; a lever pivotally associated with said bracket; a spring acting on said lever, and a link connection between said lever and said hub.V

2. An electric switch comprising a bracket having an attachment portion and having means for carrying ahub; an insulating hub mounted in said hub carrying means for rocking movement; said hub comprising a pair of insulating discs held in concentric relationship by a screw; a head and nut at the ends of the screw; said head and nut forming trunnions engaging in said hub carrying means; movable contact members on said hub: stationary contact members; means for carrying said stationary contact mem bers; a crank associated with said hub, and a hollow boss in said bracket adapted to receive a sliding member for operating said crank. y i

3. An electric switch comprising a bracket having an attachment portion and having means for carryinga hub; an insulating hub mounted in said hub carrying means for rocking movement; Said hnb comprising a. pair of insulating discs held in concentric relationship by a screw; a lieadand nut at the ends of the screw; said head and nut Jforming trunnions engaging in said hub carrying means; movable contact members on said hub; stationary contact members means for carrying said stationary contact members; a crank associated with said hub; said crank being mounted on said screw between said discs, and a hollow boss in said bracket adapted to receive a sliding member for operating said crank.

In witness whereof I affix my signature.

JOHN HERBERT HEWITT. 

